1. Field of the Invention.
The present invention relates, generally, to medical methods and devices. More particularly, the invention relates to a method to isolate, image, evaluate and quantify cutaneous nerves for establishing a diagnosis, for studying nerve regeneration and/or for measuring response to treatment. The invention has particular utility in neurology for diagnosis of diabetic neuropathy and other disorders of peripheral nerves; and in dermatology; immunology and wound healing. The invention is also useful for investigators doing research on cutaneous nerves. The invention is further useful for pharmaceutical industry to determine the effect of a new drug on wound healing or on the cutaneous nerves.
2. Background Information.
In the past, various devices and methods have been used or proposed in the diagnosis of nerve abnormalities in the dermis including nerve biopsy and skin biopsy. Nerve biopsy has been judged as unacceptable for many uses. It requires a long incision and there is a possibility of infection. It leaves the patient with a permanent sensory loss on the ankle and foot. The same area is susceptible to future infection (especially if a diabetic patient) and dysesthesias (spontaneous pains in the skin). The information obtained is often not directly related to the patient's problem. Skin biopsy is a new procedure and although promising is as yet untested. Insofar as is known, no one has isolated epidermal nerves by separating and removing an epidermis sample, particularly using a skin blister technique, for the purposes discussed above, either alone or in combination with skin biopsy.
Several publications report on making the skin blister. The first was by Kiistala in 1964. Most of the work on the blisters has been on the regrowth of the epidermis, changes in the capillaries, and chemical and cell composition of the blister fluid. None of the work has involved the nerves in the epidermis and none have involved studies of the effects of drugs on the nerves in the roof of the blister. One study looked at the nerves in the underlying dermis in wound healing after blister formation and one studied the role of cutaneous nerves in wound healing.
Despite the need to isolate epidermal nerves by a skin blister method for the purpose of evaluating and quantifying the epidermal nerves which overcomes the disadvantages, shortcomings and limitations of the prior art, none insofar as is known has been developed. Accordingly, it is an object of the present invention to provide an improved method and apparatus which overcome the limitations and shortcomings of the prior art.